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Internet-Intranets-Extranets. Pindaro Demertzoglou Lally School of M&T. How the Internet Started. The ARPANET, created in 1969, connected computers at UCLA, Stanford, University of Utah, and University of California at Santa Barbara.
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Internet-Intranets-Extranets Pindaro DemertzoglouLally School of M&T
How the Internet Started • The ARPANET, created in 1969, connected computers at UCLA, Stanford, University of Utah, and University of California at Santa Barbara. • Then, the military liked the idea for distributed decision centers. • Today, the Internet connects computers all over the globe and supplies information to people of all ages and interests. • The Internet is not owned or operated by any single corporation or government. • The Internet is based on a network of networks.
IP Addresses • Static IP address – permanently assigned IP address • Dynamic IP address – temporarily assigned • An IP address is a series of numbers, such as 204.127.129.001 • It is separated into four sections by periods • Each section’s number cannot exceed 255
Domain Names • People find it difficult to remember long strings of numbers, so host computers also have names called domain names • Domain name – “fully qualified domain name” (FQDN), usually typed in all lowercase • Key component of URLs and e-mail addresses • Lallylab2.mgmt.rpi.edu/mis lallylab2.mgmt.rpi.edu is the domain name (128.113.9.243)
Registering a Domain Name • http://www.google.com/a/cpanel/domain/new • http://www.register.com/ • http://smallbusiness.yahoo.com/domains/
TCP - IP • Transmission Control Protocol (TCP) • Breaks messages into packets and specifically into octets (eight bits) reliably and in the correct order. • Internet Protocol • Addresses packets from one computer to another.
Internet Statistics • World Statistics • http://www.internetworldstats.com/stats.htm Language Statistics • http://www.internetworldstats.com/stats7.htm Top 20 Countries • http://www.internetworldstats.com/top20.htm
WWW • List of www browsers • http://en.wikipedia.org/wiki/List_of_web_browsers • Web Server Statistics • http://news.netcraft.com/archives/web_server_survey.html
FTP – File Transfer Protocol • Basic Facts http://en.wikipedia.org/wiki/File_Transfer_Protocol#Software • FTP Clients • http://en.wikipedia.org/wiki/Comparison_of_FTP_clients
Email Servers • List of email servers • http://en.wikipedia.org/wiki/Comparison_of_mail_servers • SMTP – POP protocols
DSL is a high-speed, digital, always-on Internet access technology that runs over standard phone lines. DSL, ISDN, and Dedicated Lines
Cable Internet Service • Cable Internet service distributes always-on broadband Internet access over the same infrastructure that offers cable television service Chapter 6: The Internet
Internet Security • Intrusion Attempts • Securing Ports • Routers and NAT • Virtual Private Networks
Intrusion Attempts • An intrusion is any access to data or programs by hackers, criminals, or other unauthorized persons • Looking for open ports is one of the most common ways of gaining unauthorized access to a network-based computer. • A port is associated with an IP address of the host computer. • A web port:http://lallylab2.mgmt.rpi.edu:80/mis/ • A list of ports:http://en.wikipedia.org/wiki/List_of_TCP_and_UDP_port_numbers
Port Scanners • Software used by network administrators and hackers to identify open ports of computers in the network. • http://www.radmin.com/products/previousversions/portscanner.php
Intranets • What is an Intranet • Technical Advantages • Business Advantages • Service Platforms • Intranets in today’s economy • Measuring Intranet ROI
What is an Intranet • It is a private information system • Built on Internet technologies • Client-server system architecture • Based usually on three-tier system • It is not a telecommunications network
Technical Advantages • Easy to learn • Fast to build • Easy to deploy • Easy to maintain • Easy to update • Easy to personalize
Business Advantages • Cheaper than deploying traditional systems • Shrinks distances • Adds to the company’s business intelligence
Business Advantages • Can link to other sources of information. • Adds “time” to a company • Through document sharing (text, drawings). • Online collaboration • Cheaper than deploying traditional systems. • Shrinks distances. • Adds to the company’s business intelligence.
Intranet Services Platform • Mail server • Web server • Indexing server • Transaction server • DB server • Data Warehouse server
The role of extranets • What is an extranet? • It is an extension of the Intranet. • It includes entities from the external environment of the company.